This section provides background information related to the present disclosure which is not necessarily prior art.
Vane cell pumps which are also called sliding vane rotary pumps are known, for example, from DE 10 2013 214 926 A1 and from DE 10 2014 212 022 A1.
It is known to provide vane cell pumps as hydraulic pumps in vehicle applications. For example, this preferably takes place in conjunction with transmissions, such as drive transmissions, which require a transmission pump for supplying their hydraulic functions such as clutch actuation, converter supply or cooling and lubrication of the transmission parts. Here, these can be, for example, both conventional automatic transmissions which are also called stepped automatic transmissions or modern double clutch transmissions.
Vane cell pumps can be, for example, of structurally simple configuration such that they can be switched into double flows in a manner which is dependent on temperature. This has the advantage that both flows of a vane cell pump convey the lubricating oil under pressure in the case of a high lubricating oil requirement, for example at high temperatures. Another application is, for example, the switching of one flow to a lower pressure level at a higher rotational speed as soon as the volumetric flow of one flow is sufficient.
One general aim during the development of vehicle components is low manufacturing, operating and maintenance costs.
In order to meet the aim of low manufacturing and maintenance costs, it is known to configure a vane cell pump which is provided, for example, as a transmission pump, such as an abovementioned double flow vane cell pump which is controlled, for example, in a manner which is dependent on temperature, in what is known as a cartridge design as one unit which has been completely preassembled and tested. A vane cell pump of this type of cartridge design can be configured, for example, as a plug-in transmission pump module which can be manufactured inexpensively independently of the transmission, since this happens, for example, in a completely or partially automated manner on account of the free accessibility, and/or can be assembled manually with little time expenditure, can likewise be joined to the transmission with minimum expenditure and, in the case of damage, can be replaced equally simply and rapidly.
A multiple flow vane cell pump of cartridge design comprises a rotor which is mounted such that it can be rotated about a rotational axis and is connected or can be connected to an output shaft, for example, of a transmission or a motor, such as an electric motor, a hollow-cylindrical contour ring with an inner circumferential face, which contour ring is arranged between two side plates, of which one is configured as a bottom plate and one is configured as a pressure plate, the cylinder axis of which contour ring runs parallel to the rotational axis, for example coincides with the rotational axis. If the drive of the rotor is provided from the bottom plate which lies opposite the pressure plate, the said bottom plate is also called a drive plate. The rotor has a plurality of conveying elements which can be moved radially with respect to the rotational axis and, during a rotation of the rotor, are pushed against the inner circumferential face. The latter is shaped in such a way that a number of preferably crescent-shaped conveying spaces which in each case form a pump section are configured, which number corresponds to the number of flows. The said conveying spaces are passed through by the conveying elements during a revolution of the rotor, a number of pump sections which corresponds to the number of flows being formed with in each case one suction region and in each case one pressure region. Pressure faces, what are known as pressure kidneys, are configured in the pressure plate in accordance with the pressure regions. Fluid connections, via which the vane cell pump conveys, in particular sucks, a fluid, such as lubricating oil, for example from a sump, and pumps it to consumers and/or consumption points within the transmission, can be kept clear by the bottom and/or pressure plate or can be provided therein.
For sealing with respect to a receptacle for the vane cell pump of cartridge design, which receptacle is provided in a transmission housing, a seal arrangement is provided on the vane cell pump with axial seals in the region of a side plate and/or radial seals on the outer circumference, for example as an alternative or in addition, in the region of the contour ring.
A conventional seal arrangement 100 (shown in FIG. 1) for a double flow vane cell pump 200 of cartridge design comprises a first seal ring 110 on the circumference of a side plate 210, for example an O-ring. A shaft leadthrough 220 for a drive shaft which can be connected or is connected to the rotor of the vane cell pump 200 is provided in the side plate 210. A second seal ring 120, for example a shaped seal, is arranged circumferentially around the shaft leadthrough 220. A first fluid connection 230 (also called a primary outlet) of a first flow of the vane cell pump 200 and a second fluid connection 240 (also called a secondary outlet) of a second flow of the vane cell pump 200 are provided in the side plate 210. Both the first fluid connection 230 and the second fluid connection 240 open into a common region 130 of the seal arrangement 100 between the seal rings 110, 120, which region 130 is sealed towards the outside by the first seal ring 110 and towards the inside by the second seal ring 120. In this way, both the first and the second flow of the vane cell pump 200 deliver into the region 130 at the same pressure level which forms the system pressure p1. The entire region 130 which is under the same system pressure p1 is sealed by means of the seal rings 110, 120 with respect to the ambient pressure p0 which prevails outside the region 130. A face 250 of the side plate 210, which face 250 is delimited by two circles which are shown using dashed lines and lies within the region 130 is required for supporting a disc spring which presses the side plate 210 against the contour ring which lies underneath. A captive securing means for the side plate 210, which captive securing means is configured by way of a circlip at the shaft end, requires the shaft leadthrough 220 through the side plate 210.
In relation to operating costs which are driven substantially by energy costs, it has been shown that it is advantageous, in the case of a plurality of flows, to switch one or more flows to a lower pressure level, for example, apart from one flow, depending on the operating point, the plurality of flows being guided separately out of the vane cell pump.
FIG. 2 shows another conventional seal arrangement 1000 of a vane cell pump 2000 of so-called stand-alone design. The stand-alone design differs from the cartridge design by way of a dedicated housing which is formed by way of a corresponding recess in the corresponding part in the case of the cartridge design. As a result, merely a seal of the flows is required in the case of the stand-alone design. A shaft leadthrough 2200 for a drive shaft which can be connected or is connected to the rotor of the vane cell pump 2000 is provided on an end side 2100 of the housing of the vane cell pump 2000. Moreover, a primary outlet 2300 of the first flow of the vane cell pump 2000 and a secondary outlet 2400 of the second flow of the vane cell pump 2000 are provided on the end side 2100. The seal arrangement 1000 comprises a first seal ring 1100 which surrounds the primary outlet 2300 and a second seal ring 1200 which surrounds the secondary outlet 2400. The first seal ring 1100 and the second seal ring 1200 press as the only spring elements against the end side 2100. The first flow and the second flow can be operated at different pressure levels p1, p2 as a result of the separate seals of the primary outlet 2300 and the secondary outlet 2400 both with respect to one another and with respect to the ambient pressure p0.
In the case of the vane cell pump 200 (shown in FIG. 1) of cartridge design, this is not possible on account of the surface 250 which is necessary for supporting the side plate 210. In the case of this vane cell pump, the flows are guided jointly out of the pump at a common pressure level p1.